As cloud adoption picks up it will stir up networking stack..not only that telecom stack…precisely reason the great visionary bill gate picked up skpe for acquisition…and unified computing is at play again.

Here are Cisco back up plan how its affected.: Cisco’s imediate threat from software driven networking

Through compute virtualization decoupling the operating system from the underlying hardware, compute virtualization provides an extremely flexible operational model for virtual machines that lets IT treat a collection of physical servers as a generic pool of resources. All data center infrastructure, including networking, should provide the same properties as compute virtualization.it will unlock a new era of computing more significant than the previous transformation from mainframe to client-server.

The advantages of this shift bear repeating: once infrastructure is fully virtualized,any application can run anywhere, allowing for operational savings through automation, capital savings through consolidation and hardware independence, and market efficiencies through infrastructure outsourcing models such as hosting and“bursting.”But, data center infrastructure is not yet fully virtualized. While the industry has decoupled operating systems from servers, it has not yet decoupled the operating system from the physical network. Anyone who has built a multi-tenant cloud is aware of the practical limitations of traditional networking in virtualized environments. These include high operational and capital burdens on the data center operators, who run fewer workloads, operate less efficiently, and have fewer vendor
choices than they would if their network was virtualized.

Problems with non virtualized network stack in data centre:

#1. Hardware Provisioning: Although VM provisioning is automated to run on any server.But creation of isolated network (and its network policy) is done manually by configuring hardware often through vendor specific APIs.effectively data centre operations are tied to vendor hardware and manual configuration.So upgrades are difficult.

#2. Address Space virtualization:

VM’s next hop is Physical router in network.There are 2 problems which arise

i) VM share same switch or L2 network limiting there mobility and VM placements.In multi-tenant environment it leads to downtime

ii) Sharing of same forwarding tables in L2 or L3 so no overlapping IP address space.In multi tenant IP adresses should be as desired by customer.virtual routing and forwarding (VRF) table limits and the need to manage NAT configuration make it cumbersome to support overlapping IP addresses or impossible to do at scale.

#3. Network services tightly coupled with hardware design cycle:

Due to long ASIC design development times,so organizations that operate the largest virtual data centers don’t rely on the physical hardware for virtual network for provisioning or virtual network services. Instead they are using software-based services at the edge, which allows them to take advantage of faster software development cycles for offering new services